• Title/Summary/Keyword: K ion

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Ginseng and ion channels: Are ginsenosides, active component of Panax ginseng, differential modulator of ion channels?

  • Jeong, Sang-Min;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.29 no.1
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    • pp.19-26
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    • 2005
  • The last two decades have shown a marked expansion in publications of diverse effects of Panax ginseng. Ginsenosides, as active ingredients of Panax ginseng, are saponins found in only ginseng. Recently, a line of evidences shows that ginsenosides regulate various types of ion channel activity such as $Ca^{2+},\;K^+,\;Na^+,\;Cl^-$, or ligand gated ion channels (i.e. $5-HT_3$, nicotinic acetylcholine, or NMDA receptor) in neuronal, non-neuronal cells, and heterologously expressed cells. Ginsenosides inhibit voltage-dependent $Ca^{2+},\;K^+,\;and\;Na^+$ channels, whereas ginsenosides activate $Ca^{2+}-activated\;Cl^-\;and\;Ca^{2+}-activated\;K^+$ channels. Ginsenosides also inhibit excitatory ligand-gated ion channels such as $5-HT_3$, nicotinic acetylcholine, and NMDA receptors. This review will introduce recent findings on the ginsenoside-induced differential regulations of ion channel activities and will further expand the possibilities how these ginsenoside-induced ion channel regulations are coupled to biological effects of Panax ginseng.

EO Performances of the Ion Beam Aligned TN-LCD on a Diamond-like-Carbon Thin Film Surface

  • Hwang, Jeoung-Yeon;Jo, Yong-Min;Seo, Dae-Shik;Rho, Soon-Joon;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.497-499
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    • 2003
  • Electro-optical (EO) performances of the ion beam aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the DLC thin film surface were studied. An excellent voltage-transmittance (VT) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD can be achieved with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

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Adsorption and Desorption Characteristics of Methyl iodide on Silver ion-Exchanged Synthetic Zeolite at High Temperature

  • Park, Geun-Il;Park, Byung-Sun;Cho, Il-Hoon;Kim, Joon-Hyung;Ryu, Seung-Kon
    • Nuclear Engineering and Technology
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    • v.32 no.5
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    • pp.504-513
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    • 2000
  • The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver ion-exchanged zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver ion-exchanged level for the effective removal of methyl iodide at temperature up to 38$0^{\circ}C$. The degree of adsorption efficiency of methyl iodide on silver ion-exchanged zeolite is strongly dependent of silver ion-amount and process temperature. The influence of temperature, methyl iodide concentration and silver ion-exchanged level on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It would be facts that the effective silver ion-exchanged level was about 10 wt%, based on the degree of silver utilization for the removal of methyl iodide.

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Purification and Characterization of a ${\beta}$-Glucosidase from Aspergillus niger and Its Application in the Hydrolysis of Geniposide to Genipin

  • Gong, Guohong;Zheng, Zhiming;Liu, Hui;Wang, Li;Diao, Jinshan;Wang, Peng;Zhao, Genhai
    • Journal of Microbiology and Biotechnology
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    • v.24 no.6
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    • pp.788-794
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    • 2014
  • An extracellular ${\beta}$-glucosidase from Aspergillus niger Au0847 was purified to homogeneity by precipitation with ammonium sulfate, anion exchange, and gel filtration. The purified protein was composed of two subunits with molecular masses of 110 and 120 kDa. Au0847 ${\beta}$-glucosidase exhibited relatively high thermostability and pH stability, and its highest activity was obtained at $65^{\circ}C$ and pH 4.6, respectively. As a potential metalloprotein, its enzymatic activity was potently stimulated by manganese ion and DTT. The ${\beta}$-glucosidase displayed avid affinity and high catalytic efficiency for geniposide. Au0847 ${\beta}$-glucosidase has potential value as an industrial enzyme for the hydrolysis of geniposide to genipin.

Influence of the Density Gradient on the Current of the Electrode Immersed in the Non-uniform Plasma (플라즈마 삽입전극의 전류에 미치는 밀도 구배의 영향)

  • Hwang, Hui-Dong;Gu, Chi-Wuk;Chung, Kyung-Jae;Choe, Jae-Myung;Kim, Gon-Ho;Ko, Kwang-Cheol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.6
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    • pp.504-509
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    • 2011
  • The conducting current of non-uniform plasma immersed electrode consists of ion current and secondary electron emission current caused by the impinging ion current. The ion current is determined by the ion dose passing through the sheath in front of electrode and the ion distribution in front of the electrode plays an important role in the secondary electron emission. The investigation of the distributed plasma and secondary electron effect on electrode ion current was carried out as the stainless steel electrode plugged with quartz tube was immersed in the inductively coupled Ar plasma using the antenna powered by 1 kw and the density profile was measured. After that, the negative voltage was applied by 1 kV~6 kV to measure the conduction current for the analysis of ion current.

The Additional Filter and Ion Chamber Sensor Combination for Reducing Patient Dose in Digital Chest X-ray Projection (디지털 흉부엑스선 검사에서 환자선량 감소를 위한 부가필터와 Ion chamber 센서 조합)

  • Lee, Jinsoo;Kim, Changsoo
    • Journal of the Korean Society of Radiology
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    • v.9 no.3
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    • pp.175-181
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    • 2015
  • In this paper, we studied additional filter and Ion chamber combinations to reduce patient dose without decreasing image quality in digital chest x-ray projection. The experiment set 125 kVp, 320 mA, AEC mode. Ion chamber sensors was divided by 4 cases of combinations, then, we measured patient dose and calculated organ dose using PCXMC. Also, physical image assessment using MTF was performed. As a results, The surface entrance dose and organ dose were the lowest when selecting both left and right Ion chamber sensors under the same conditions of additional filter. In image quality assessment, The spatial frequency scored 2.494 lp/mm which was highest when selecting both right and left Ion-chambers and 0.1 mmCu filter. And to conclude, to select both right and left Ion chamber sensors and 0.1 mmCu filter will help for acquiring good quality image as well as reducing patient dose.

Evolution the surface morphology and mechanical properties of Polyimide induced by Ion Beam Irradiation

  • Ahmed, Sk. Faruque;Nho, Gun-Ho;Moon, Myoung-Woon;Han, Jun-Hyun;Lee, Kwang-Ryeol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.98-98
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    • 2010
  • Ion beam irradiation has been extensively used for surface modification of polymers, glassy metals and amorphous and crystalline materials at micron and submicron scales. The surface structures created by exposure to an ion beam range from dots, steps and one-dimensional straight wrinkles to highly complex hierarchical undulations and ripples. In general, the morphology of these nanoscale features can be selected by controlling the ion beam parameters (e.g. fluence and acceleration voltage), making ion beam irradiation a promising method for the surface engineering of materials. In the work, we presented that ion beam irradiation results in creation of a peculiar nanoscale dimple-like structure on the surface of polyimide - a common polymer in electronics, large scale structures, automobile industry, and biomedical applications. The role of broad Ar ion beam on the morphology of the structural features was investigated and insights into the mechanisms of formation of these nanoscale features were provided. Moreover, a systematic experimental study was performed to quantify the role of ion beam treatment time, and thus the morphology, on the coefficient of friction of polyimide surfaces covered by nanostructure using a tribo-experiment. Nano-indentation experiment were performed on the ion beam treated surfaces which shows that the hardness as well as the elastic modulus of the polyimide surface increased with increase of Ar ion beam treatment time. The increased of hardness of polyimide have been explained in terms of surface structure as well as morphology changes induced by Ar ion beam treatment.

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ION BEAM APPLICATION

  • Baba Mamoru
    • Nuclear Engineering and Technology
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    • v.38 no.4
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    • pp.319-326
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    • 2006
  • A brief review is presented on the ion beam application in science and technology. ion beams are used very effectively in various fields of science and technology, on the basis of advance in accelerator technology and experimental techniques for ion beam utilization. Recent progress in this field is reviewed in terms of the direct ion beam utilization like ion beam analysis, and the utilization of neutrons as secondary particles.

Development and characteristic study of high brightness ion source using inductively coupled plasma for focused ion beam (유도결합 플라즈마를 이용한 집속이온빔용 고휘도 이온원의 개발 및 특성연구)

  • Kim, Yoon-Jae;Park, Dong-Hee;Hwang, Yong-Seok
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.494-499
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    • 2004
  • A ion source using inductively coupled plasma has been tested in order to test its feasibility as a high brightness ion source for focused ion beam. When operating the ion source with filter magentas in front of plasma electrode for a negative ion source, lower remittances are expected. Extracted beam remittances are measured with an Allison-type scanning device for various plasma parameters and extraction conditions. The normalized omittance has been measured to be around 0.2$\pi$mmmrad with beam currents of up to 0.55 ㎃. In particular, noting that multicusp magnets have a role in decreasing the remittance as well as increasing plasma discharge efficiency, transverse magnetic field has been confirmed to be a useful tool fur decreasing remittance via electron energy control.

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